<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<script>
    // var age = prompt('你的年龄是?');
    // alert(`您今年${age}岁`);
    // // alert('您今年' + age + '岁了');
    // var uname;
    // console.log(uname + '5')
    // var age = 1;
    // var obj = null;
    // var str = '3';
    // console.log(typeof age, typeof obj, typeof str);
    // console.log(parseInt('111px120'));
    // console.log(parseFloat('3.15abfc'));
    // var num1 = parseFloat(prompt('请输入第一个数字')),
    //     num2 = parseFloat(prompt('请输入第二个数字'));
    // alert(`他们的和是:${num1 + num2}`);
    // var age = 2021 - prompt('请输入您的出生年份');
    // alert(`您的年龄是:${age}岁`);
    // console.log(Boolean(''));
    // console.log(Boolean(0));
    // console.log(Boolean(1));
    // console.log(Boolean(NaN));
    // console.log(Boolean(null));
    // console.log(Boolean(undefined));
    // console.log(Boolean('123'));
    // console.log(Boolean(12));
    // console.log(Boolean());
    // console.log(Boolean());
    // console.log(Boolean());
    // console.log(Boolean());
    function fu(num, n) {
        var num1 = num;
        return num1;
    }
    alert(fu(1.255, 1))
</script>

<body>

</body>

</html>